Lydia proposes to send an interstellar probe off in stages. The first stage, tra
ID: 1409203 • Letter: L
Question
Lydia proposes to send an interstellar probe off in stages. The first stage, traveling radially outward at 0.500 c relative to Earth, will send off a second stage traveling in the same direction as the first stage at a speed of 0.500 c relative to the first stage. Finally, the second stage will send off a third stage traveling in the same direction at 0.500 c relative to the second stage. Relative to Earth, the speed of the third stage will have a magnitude of:
a) 0.500c
b) 0.800c
c) 0.929c
d) 0.972c
e) 1.500c
I need help trying to understand this, and I'd prefer if there was some notation to the velocities so that I can better understand the order of progression for the answer.
Explanation / Answer
option c is correct
velocity of second stage wrt earth
v = (v’ + u)/(1 + v’u/c2 )
v = (c/2 + c/2)/(1 + (1/2)(1/2)) = 4c/5
velocity of third stage wrt earth,
v = (c/2 + 4c/5)/(1 + (1/2)(4/5)) = 0.929c
option c is correct
v' is the relative velocity of second stage with respect to first stage and u is the velocity of first stage (for first equation) ....this equation is used twice....the other time for second and third instead of first and second in equation
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.